Workshops on Using the GPS Method to Determine Curve Advisory Speeds

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M.P. Pratt, J.D. Miles, J.A. Bonneson

Publication Date:

December 2009


Curve warning signs are intended to improve curve safety by alerting the driver to a change in geometry that may not be apparent or expected. However, several research projects conducted in the last 20 years have consistently shown that drivers are not responding to curve warning signs or complying with advisory speed plaques. A new engineering study method was developed to improve consistency in curve signing and driver compliance with advisory speeds. This report documents two activities that were conducted to promote implementation of the new method. One activity is the development of a software program to measure curve geometry while driving through the curve. The geometric data are then used to determine an appropriate curve advisory speed and to select effective, curve-related traffic control devices. The second activity for this project was a series of workshops that described use of the new method. The workshop provided a mixture of classroom discussion and hands-on training activities for the participants. The workshop participants generally indicated that they believed the new method would benefit their districts and looked forward to implementing it. Recommendations for future research in this area were identified.

Report Number:



Traffic Control Devices, Warning Signs, Speed Signs, Highway Curves, Speed Management, Trucks, Traffic Speed

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